Variable delivery pump or motor



March 22, 1938.

E. K. BENEDEK VARIABLE DELIVERY PUMP 0R MOTOR Fil ed Oct. 24, 1934 5 Sheets-Sheet l L 2 ELEK. KEEN March 22 1938. E. K. BENEDEKY 2,111,658

VARIABLE DELIVERY PUMP OR MOTOR Filed Oct. 24. 1934 5 Sheets-Sheet 3 6' wucwtor FEE E ILEK KEENEDEK Skim/M44 4,

March 22, 1938. 7 BENEDEK 2,111,658

"ARIABLE DELIVERY PUMP 0R MOTOR I Filed Oct. 24, 1934 I 5 Sheets-Sheet 5 I v 68 I 40 4a 45 46 ILEKKEIENEEJEK Patented Mar. 22, 1938 UNITED s'rA'rl-zs PATIENT orr ca Elek K. Benedek, Bncyrus, Ohio Application October 24, 1934, Serial No. 149,745

.12 Claims. (c1. nos-1m) This invention relates to variable delivery pumps and motors oi the radial piston type and has for its primary object the provision of a simple emcient and 'hydrostatically balanced of a unitary piston and double roller assemblmso arranged, that the rollers are capable of high speed operation on their respective track members while they support thepiston unit on specially arranged capillary anti-friction elements.

Another object of the invention is in the provision of novel cylinder barrel or rotor and by drostatlcallybalanced valve pintle assembly and means for the lubrication of said assembly.

Further novelty of the invention lies in the provision of adjustable supporting means for said rotor or cylinder barrel, to take up the wear between said-rotor and the pintle and maintain a desirable clearance space therebetween for the purpose of limiting slip and obtaining sumcient lubrication for high speed bearing support. Another object 1.; in the provision of special bearing surfaces in a casing, to adjustably support the piston reactance means and to remov ably secure said piston reactance means in the a casing.

- Another object is in the provision of a rigid g support for both ends of a main vaivepintle.

Other more specific objects and advantages will appear from the description of an illustrative embodiment of the invention shown in the drawings.

In the drawings: 1

Fig. 1 isa partial transverse sectional view of the said embodiment of the pump, taken on the lines lv-l in-Figs. 2 and 3 respectively;

Fig. 2 is a longitudinal sectional view of the pump taken substantially along the line 2-2 in Fig. 1, showing two sets of diametrally opposite pistons and their carrying rollers (turned 30 from their positions according to Fig.1). the view being taken through the major axis of the strokecontrolling cam or track assembly of the pump: Fig. 3 is a longitudinal sectional view of the pump, taken on line 8-3 in Fig. 1, through the minor axis of the stroke controlling cam or track asse b Fig. 4 is a transverse sectional view taken on the line dt in Fig. 2, showing the variable stroke cam mechanism and the cooperative rollers in the maximum stroke position, the rollers being shown in elevation for clearrfess in illustration;

Fig. 5 is a transverse sectional-view taken on the line t-t in Fig. 3, showingjhe variable stroke cam mechanism and the cooperating piston actuating rollers in their minimum stroke position;

Fig. 6 is an isometric perspective view of one 15 of the stationary parts of the variable stroke cam.

mechanism; and

Fig. 7 is a longitudinal fragmentary section take on the plane of Fig. 2, showing the taperpintle and.v barrel and (diagrammatically) the operative clearance therebetween.

The pump disclosed for illustration is enclosed in a generally cylindrical casing, comprising a cylindrical central main-body section it, having an integral end plate portion it' and a hubportion It" projecting therefrom. The opposite end of the casing is closed by an end cover it rigidly secured to the open end of the main body section it and a smaller cover it secured to a circular flange of the cover it as by cap screws ,N. A plurality of laminated shims it are provided as a bearing adjustment (to be later described) and are positioned between the parts It and it.

The inner surface of the main casing is fln- 35 ished to form a continuous cylindrical surface as at 6! (Fig. 1). to iornr cooperative wormn'g' surfaces with the piston operating cam assembly 43-43 and 48 respectively, as will be hereinafter described. The casing portion "1'" carrying the 40 hub portion ill", for the main pump-connections. (not shown in the drawings) is provided with a central counter bore as at Ma toreceive antifriction bearing means 30, 3i and 32, and the hub portion I0" is provided with central bore ll to 45 rigidly secure and receive an enlarged portion lie of valve pintle i5.

The valve pintle i5 is of the four port hydrostatically balanced type, having two pairs of diametrally opposite ports as at l6, l6 and l1, ll to provide for fluid distribution between the pump mains and rotary individual cylinders 33. Each pair of ports I8, I6 H, H supply and discharge the fluid under the same-pressures and it will be seen that the fluid at the working surfaces of the 5 pintle it will be in hydrostatic equilibrium with respect to the piston loads at all times.

The valve pintle i5 is further provided with a slightly tapered working section l5' in cooperation with a similarly shaped and fitted barrel bore 23 of the piston carrying rotor or barrel 25. The working Section l5' is provided with small operating clearance, say one-half to one thousandth of an inch, adjacent the barrel bore in order to provide clearance space for lubricating fluid supplied as slip from the operating fluid of the pump. The small clearance space contrary to common journal mounting practice is not eccentric but concentric with the inner bore 23 of the barrel so that fluid may be drawn between the cooperative barrel and pintle surfaces not only by the dynamic action of rotation, but by the capillary attraction of the clearance space around the entire periphery of the pintle.

In order to maintain the aforesaid concentric clearance space for forced lubrication by capillary attraction, I provide double end supports for the large and small ends of the pintle, shown as needle bearing rollers i8 and I9 respectively in appropriate recesses i5 and I5"; (see Figs. 2

. and 3). To facilitate the assembly of the pintle IS with its double row of needle roller bearings in the barrel 25 I provide appropriate shoulders as at l5b and I50 respectively, so that when the needle rollers are packed with heavy grease they will stay firmly enough in their recesses to facilitate slipping the barrel over the pintle without disarranging the needles. For the proper functioning of my needle bearings I8 and It, be it known, that contrary to the teachings of the prior art and prior bearing practice, I do not completely fill the recesses with the rollers but when the recess is full I take out one or two of the needles and temporarily fill the spaces left thereby with heavy grease so that when the needies are finally disposed between the pintle and cylinder barrel, there will be a definite predetermined clearance between the needles so that the capillary force will maintain and provide separator films between each pair of needles which film is substituted for the cages of antifriction bearings of present commercial practice. Such present practice, using cageless rollers, advises packing the rollers tight so that there will be metal to metal contact between the adjacent needles and thus there is no space for a capillary oil film and, further, individual rotation of the rollers cannot take place. Contrary to the aforesaid practice, I provide a positive looseness and flexibility for the needle rollers for the above described purpose. The needles l8 and i9 being disposed in rotary contact with their respective races l5, l5" and the adjacent barrel bore surfaces are permitted flexibility of movement for the capillary action of the lubricating fluid, and the pump may be operated at a considerably higher speed than possible with pumps heretofore known.

In order to further assure not only perfect lubrication of the needles l8 and is in their re cesses, but also lubrication and sealing of the working surfaces of pintle and barrel during the suction periods of the pistons and during low pressure operation of the pump respectively, when slip lubricant is reduced to an abnormal minimum, I provide a chamber as at 26', Figs. 2 and 3, to retain the slip fluid of the high pressure operating cycles for utilization during the low pressure cycles. discharge of excess slip, I provide a pressure re- In order to provide for the lief valve comprising a valve seat 20, a ball check 2| and spring 22 assembled in appropriate axial bores of the barrel 25 including the chamber 21. When the chamber pressure reaches a predetermined value, measured by the compressive strength of the spring 22, the fluid under the ball will lift the ball, the fluid finally escaping from the chamber 27 through radial bores 28 in the barrel, (shown at the base of the impeller shaft portion 29) It will be seen that under normal operation due to the pressure in chamber 26' a great part of the slip which has already passed the ports l6 and ii, iii and H respectively into space 2% will be forced to flow in the opposite (left hand) direction in the clearance space between the pintle and barrel 25 and thus seal said clearance space against sucking of air as well as flood the working surfaces until the fluid reaches the needles of the bearing [8 where it will be retained in the spaces between the needles, effecting lubrication thereof, until the excess slip flow reaches the clearance space 65 around the pintle adjacent the left hand supporting means of the barrel. I

The barrel 25 is provided with adjustable antifrictionbearing means as at 3030, previously mentioned, in such manner that whereas the inner race members 3l-3l of the bearings are rigidly secured to the respective ends of the rotor, the outer race members 32-32 are axially adjustable respectively in thecounter bore We of the body plate 1' and in the central opening of the cover plate H. The purpose of the bearing adjustment is twofold. First when the pump is new, pintle and cylinder fits are close and any binding at these surfaces may result in burning or scoring of the parts so fitted. During this period provision of a liberal number of shims as at i3 allows the bearings to operate freely, but after some operation of the pump when the pump appears to operate freely and function properly, some of the laminated shims may be removed from the-shim assembly by removal of the plate l2. Upon replacement of the plate l2 the abutment flange i212 thereof axially shifts the outer races 32 in their respective bores taking up all play in the bearings and sometimes slightly preloading the bearings, meanwhile slightly adjusting the operative clearance space between the pintle and cylinder at the frustro-conical working surfaces. It is evident that, by reason of provision for this bearing adjustment after considerable useful service and some wear, the pump .may be reset forfurther long periods of service in which both freedom of operation of the bearings and proper clearance between pintle and rotor obtain. The clearance space in the counter bore 24 adjacent the shoulder l5b, likewise the space 26', are ample to allow such slight axial adjustment of the bearings 30 and the barrel 25 therewith as will ever be necessary.

Fig. 7 illustrates diagrammatically that when the pintle and barrel are adjusted relatively axially the clearance space is adjusted as by movement of the barrel from full line position at 25 (affording enlarged clearance space 23a) to dotted line portion at 25' (affording diminished space 23b).

The piston rotor or barrel 25 is further provided with a central web portion M, a portion of which is shown in section at the top of Fig. l, the web being cut away to form evenly distributed outwardly open radial guideways 35 for the piston crossheads 31 of radial pistons 38 operating ,iimt

in cylinders it in the barrel. The piston crossheads ii are, as shown, integral with the radial pistons 36. Each piston crosshead 31 has a transverse bore which serves as the outer race for piston crosspin needle rollers 30 to rotatably support cross or roller pins 30 having,- as shown, rollers dttt secured thereto for contact with the operating cam tracks as will be later described. The pistons with their integral heads, crosspins it and rollers d form a piston and thrust subassembly in which the needles 3% are retained in position by the rollers it themselves, all as more fully described and claimed in my copending application, Serial No. 726,962, filed May 22, 1934. The disposition of the needles in the piston crossheads is the same as the disposition of the barrel needles it and id, that is, the needles afford antifrictional and capillary mountings for the supported elements, in this case the pins 30. Proper provision is made to secure antifrictional characteristics for the operation of needles 3% and capillary force feed lubrication thereof for the purpose of perfect lubrication of the pins 30 and to provide high speed bearing support for said pins in the crossheads 371. Since the driving of the piston rollers it-d0 upon their associated cam surfaces, indicated at M, at commercial speeds is such as from 1000 R. P. M. to 2000 R. I ll/L, it is imperative to reduce not only rolling friction between rollers t0 and tracks M but provision must also be made to keep the axes of roller pins 39 parallel with the axis of rotation of the rotor 25. To eliminate substantial wear between the crossheads t1 and the guideways 35 of the web 34, the width of the web and of the crosshead is substantially wider than the diameter of the pistons. In keeping therewith large and heavy rollers are used to assure a, positive contact simultaneously between the both rollers 40 of eachpin 39 and their associated track 44 to provide free rolling contact therebetween. The large rollers are also an element in accomplishing the suction strokes of thepistons centrifugally andfor fly wheel eflect as will be later mentioned. The piston heads are circular in cross section adjacent their guideways 35 in order to allow slight rotation about the axes of the pis-- tons, necessary for transverse alignment of the rollers during-operation. Thus the speed and piston load will hold the rollers in continuous rolling contactwith theirrespective'tracks. Considering the enormous relative rotation of the rollers 40 driven by the rotor-23, .when therotor makes, say 1000 revolutions ,per minute, it is evident that in order to assure free true rotation between rollers 40 and tracks 44 it is necessary that the crosspins 39 freely rotate in the crosshead. The free rotation of rollers 40 thus assumes the free rotation of the respective pins 39, whic again assumes the proper mounting of the pi It was not possible heretoforeto secure proper mounting for such high-speed pins as 30 due to thelack of lubrication with ordinary antiiriction bearings or sliding friction bushing bearings due to the greatcentrifugal force which tends to and does remove the lubricant from such bushings and from antifriction bearings which. are packed tightlyin their races. Due to the provision of adequate space between the needles such as will allow them to roll freely while still being ll enough and of sufilcient number to function as capillary retaining means for the lubricating fluid, the previous difficulties in sup- J porting similar cross pins are overcome.

With the increased efliclency made possible by the above described mountings etc. operation under much higher pressures was made possible but such higher pressures in conventional designs of pumps resulted in hydrostatic unbalance particu-v larly at the working surfaces of the pintle and rotor and. thus imposed a limitation to development along conventional lines using greatly in-.

creased pressures. To overcome this limitation,

I have provided a two cycle pumping unit, wherein; during every revolution of rotor 25 each piston carries out two pressure and two suction strokes. Pumps of this kind heretofore known had no provision for variable discharge and suction and I have, therefore, designed a novel variable delivery cam mechanism having the desirable hydrostatic balance operating characteristics above referred to, which mechanism will now be described.

The cam mechanism (see Figs. d, 5 and 6) comprises a pair of diametrally opposite circular members il-M and a pair of stationary members tit-db, the latter having straight planar working contours as at 5t50' and circular supporting surfaces adjacent the complementary inner surfaces of the casing.

The adjustablecam sections M and di' have inner circular profiles as at M which support the rollers t0, and outer circular profiles as at db and 05 which serve as stops when the cams are in their maximum stroke positions (separated as shown in Fig. 1). In addition to the circular sections of the adjustable cams, these cams are provided with a pair of narrow rectangular rib portions as at B3 which'serve as guides for the cooperative planar sided portions 41-41 (Fig. 3) of the stationary cams 46-46.

The ribs 43 are closely fitted between the flat I inner end surfaces of the casing and the portions 41 of the stationary cams, so that during the operation of the pump the composite cam tracks 44-44 etc. may be varied in operative effect by shifting the circular members 41-4! as by means of control rods 42 and 42', see Fig. 3. r

Fig. 5 shows the adjustable cams in position such that the cam profiles 44 and 44' form an exact circle, and in this setting it is obvious that rotation of the barrel will-cause no pumping action as the rollers will merely revolve in a circle.

It will be seen that the cam members 4l4l" have certain inherent advantages from the stand point of manufacture due to their simple form. When the two parts 4i and 4| are finished at their adjacent ends as at 59, said parts may be fastened together as one body, and both track profiles 44 and 44' formed as one operation; likewise flnished and-ground.

It will be observed furthermore, that by means of a suitable spacer between the abutments 59, Fig. 4, they may be clamped again to form virtually a one piece body to simultaneously turn and finish the outer circular surfaces 45, 05'

which serve as stops by abutting the interior peripheral surfaces of the casing. This simple method assures extreme accuracy and greatly reduces cost.

Referring to Fig. 6, an isometric view of ,one of the stationary cams t0, it will be seen that this part is formed with a cylindrical back to precisely fit the cylindrical bore 6i of the main casing part it and a chordal flat portion M to I form acontinuation of the profiles it when separated as shown in Fig." 4. In order to avoid any shock or bump oi the rollers, as these rld'e onto and off the flat surfaces, it is imperative that the chordal track surface portions 41 of the stationary cams 46 be absolutely tangential to the semi-circles 44 and 44' of the adjustable cam members 4|, 4|. Therefore, the adjustable track members slide directly on the members 46, 46' and the sliding surfaces in mutual contact are very accurately fitted. Since the surfaces 41 are stationary and parallel with the end covers of the casing 'as at Ila .e. g., the rib portions 43 will be positively guided and supported so as to eliminat all vibration and tendency for the cam surfaces t get out of alignment.

It will be further observed that the stationary earns 46 are easily lined up with the parallel guide surfaces 58 of the adjustable members 4| about the cylindrical surface of the casing after which alignment dowel pins 5|, (Fig. 3) may be fitted in place in both stationary cams to prevent rocking thereof consequent upon wear of the sliding surfaces. Figs. 1, 3 and 6 show that a circular recess 49 is cut in the central portion of the member 46 in order to clear the rotary web 34 of the cylinder barrel 25.

In operation of the pump, assuming the control members 42 are directly fastened to the adjustable cam members as at 60, the relative positions of these members determines the stroke of the pistons- The members 42 may be mechanically or manually or otherwise adjusted and/or locked, and the adjustment may be automatically effected in connection with other mechanisms as desired. I b

It will be noted that between the extreme stroke position Figs. 1 and 4 and the neutral posi tion of Fig. 5 a continuous stroke adjustment for any desired stroke is possible without jerk or discontinuity of the pumping operation.

When the machine operates as a pump at commercial speed, such as earlier mentioned, the large mass of the piston and roller assemblies is suflicient to effect full suction strokes of the pistons, whereby I may eliminate from the structure expensive devices for positively moving the pistons outwardly. Thus, the large .rollers are not only advantageous for the purpose of reducing track friction but they also provide the necessary suction strokes for the pistons and sumcient flywheel effect to the rotor to obviate the necessity for a separate flywheel.

It will be further seen that I have greatly improved the eiiicienoy of the machine by the provision in the rotor of a fluid receiving chamber to store up fluid escaping slip along the plntle, but also I have provided a relief valve which, will build up pressure in the chamber, to thus force the slip fluid backward in the opposite direction and thus utilize it twice for lubrication. The excess of fluid in the chamber 26' will be relieved through the valve 2|, when the built up pressure reaches the set pressure of the 22.

The working fluid will be properly distributed through ports l6, l6 and l1, l1 irrespective of the direction of the rotation of the pump. Reversal of the pumping action may be effected by the reversal of the direction of rotation of the impeller shaft. The pump may also be reversed by a degree rotation of the cam mechanism by appropriate means (not shown). It will be seen that my cam mechanism is supported at all times on cylindrical surfaces in .the casing, and upon cylindrical mating surfaces of the stationary earns 46; consequently it is clear that by an aprelief valve spring propriate mechanism for effecting such 90'degree rotation the adjustable cams and stationary cams may be adjusted to effect reverse pumping as a unit. The control means would, of course, also have to be rotated with the cam means in order to maintain proper control of the working fluid.

It will be further seen that in operation, due to the hydrostatic balance of fluid between the working surfaces of the plntle and cylinder barrel, the main bearings 30 of the latter will be practically unloaded. It will be easier to visualize the unloading of the bearings if we realize that in case of a 4 inch pintle, and hydrostatic unbalance the plntle load reacts on the barrel with an unbalanced area of at least 4" 8"=32 square inches, which creates a total of 32x3000= 9 6,000# on the cylinder bearings, thus loading each of the bearings with 48,000#. This bearing load at 8000# per square inch operating pressure would require two bearings, each capable of supporting a twenty-four ton load which requirement would be diflicult to fulfill. If a partial balance would reduce above estimated bearing load to 50% of its-full value, there is still a hearing load of twelve tons which requires a very strong bearing. From the above illustration, it will be seen that it is more important to unload the pump by my novel structure than to have a one' piece adjustable eccentric in view of the fact that the replacement of non-hydraulic parts is much more simple and inexpensive than the replacement of hydraulic parts such as pistons and cylinders, pintle and barrel, for the simple reason that whereas the hydraulically functioning parts are closely and individually fitted together and are not interchangeable for manufacture, the mechanically functioning parts are more or less interchangeable and their replacement and cost is much lower than the replacement of hydraulically functioning parts.

While the reliable and eflicient functioning of the device is assured by the compactness and simplicity of the device it must be remembered that the speed ratios between the rotating roller pins in the needle rollers and the rollers on their tracks are of equal importance. It is evident from the design that the needles 38 are compelled to rotate about their own axes with enormous speed in order to maintain rolling contact between the roller and their race members and it was previously believed impossible for any antifriction element to carry out such high speed r0- tation about individual axes when the load is so great as 3000# per each square inch of piston area. However, I have found that by maintaining the same speed ratio between rollers and track as between roller pins 39 and needles 38, the needles will carry their loads without being damaged. In the present structure for every revolution of the rotor the rollers 40 will have the same number of individual rotations as the needles 38 about their axes. disclosure hereof (neglecting the elliptical shape of the tracks 44) shows that the ratio between cross-pin and needle diameter is the same as the.

A ratio analysis of the barrel, a radial flange on the barrel in the zoneoi the plungers, radial guideways in the flange for the plungers, reactance engaging means on the plungers respectively and disposed alongside both faces of the flange, adjustable reactance means disposed along both faces'oi the flange and providing a continuous reactance track for the reactance engaging means in all adjusted positions oi e reactance means, said reactance means incl ding a pair of symmetrical reactance i elements diametrically opposite to each other and adjustable toward and away from the axis of rotation of the barrel, each of said reactance elements having two axially spaced curved track portions, the track portions of one. element del fining without track portions of the other element continuous curved tracks coaxial with the barrel when the elements are adjusted to their innermost position, means mounted in the casing and having tneclr portions tangential to the track 5 portions of the elements and arranged to bridge the spaces between the adjacent ends of the track portions of the elements when the elements are separated and to form with said curved track portions continuous tracks, said track portions of 9 said last named means being spaced apart axially of the barrel and accommodating the outer marginal portion of the flange therebetween.

2. In a hydraulic pump or motor of; the rotary radial plunger type, including a casing, a rotatable barrel, a plurality of plungers carried by the barrel, a radial flange on the barrel in the zone of the plungers, radial guideways in the flange for the plungers, reactance engaging means on the plungers respectively and disposed alongside 0 both faces of the flange, adjustable reactance means disposed along both faces of the flange and providing continuous reactance tracks for the re- 'actance engaging means in all adjusted positions 0i thereactance means, said reactance means in- ,5 eluding a pair of symmetricalreactance elements arranged diametrically opposite to each other and adjustable toward and'away from the axis of rotation of the barrel, each or saidreactance elements having two axially spaced curved track n portions defining continuous curved tracks coaxial with the barrel when the'elements are adjusted to their'innermost positiombearin'g blocks in. the casing having chordal bearing surfaces, complementary surfaces on the said elements and in engagement with the said chordal surfaces for supporting the elements for said adjustment, said blocks having chordal track surfaces tangential to the track portions or the elements and arranged to bridge the spaces between the adjacent ends of the track portionsoi the elements when the elements are separated from each other and supported on the chordal bearing surfaces, and to provide with said curved track portions continuous tracks for the reactance engaging means, and

, each of said blocks having a groove disposed toetween the chordal track surfaces thereof for 1 accommodating the outer marginal portion of the barrel flange as the barrel rotates.

3. Ina hydraulic pump or motor of the rotary radial plunger type, including a casing, a rotatable barrel, a plurality of plungers carried by the barrel, a radial flange on the barrel in the zone of the plungers, radial guideways in the flan e tor the plungers, reactance engaging means on the plungers respectively and sition,

.-the barrel when curved tracks coaxial with the barrel when the elements are adjusted to their innermost position,

bearing blocks mounted in the casing and having chordal bearing surfaces at their lateral margins, chordal bearing surfaces on the elements complementary to those of the blocks for supporting the elements, said elements being reduced in width adjacent the bioclrs, chordal raised portions on the blocks received between the reduced width portions of the elements and lying alongside thereof and having track surface portions tangential to the curved track portions and forming continuous tracks with the curved traclr portions when the elements are separated, and said reactance engaging meansspanning said reduced width portions and acent track portions; oi the blocks.

a. In a hydraulic pump or motor of the rotary radial plunger type, including a casing, a rotatable barrel, a. plurality of plunger and cylinder assemblies carried thereby, adjustable reactance means therefor providing a continuous reactance path for the assemblies in all adjusted positions, said means including a pair of reactance elements having semi-circular reactance track portions arranged diametrically opposite to and symmetrically with respect to each other, said elementsbeing adjustable toward and away from the axis of rotation of the barrel to different adjusted positions for adjusting the strokes of the assemblies, the reactance track portions defining a continuous-circular track coaxial with the barrel when the elements are adjusted to their innermost posaid elements having outer abutment surfaces defining a cylindrical surface coaxial with the elements are adjusted to their outermost relative-position, said casing havring a cylindrical wall in'the plane oi the elements and surrounding the same and having the same radius as'the said cylindrical surface of the ele- V ments and coaxial with'the barrel. whereby the bridging the space between the ends 01 the semicircular track portions of the elements when the elements are separated and forming with said semi-circular track portions a continuous closed track.

5. In a hydraulic pump or motor or the re a radial plunger type, including a casing, a rotatable barrel, inder assemblies carried thereby, valve ms for the assemblies, adjustable load reactance a i -for the assemblies pro for the assemblies in all adjusted reactance means, said load reactancemeans including a pair of separable elements at ed diametrically opposite to other and mid ele ments being movable toward and awayirom the axis of rotation of the barrel and he i: i i it an trical curved load reactance trash portions defining a continuous track when the elements m adjusted to their most position, said elements in ardon tions of the iii a continuous path and a plurality of plunger and cylbeing in end to end abutting relationship when adjusted to their innermost position and having slots opening through their ends, said slots being tangential to the track portions of the elements adjacent the ends of the elements, and separate load track means mounted in the casing and having chordal track portions respectively accommodated in said aligned slots and bridging the space occasioned between the elements consequent upon separation of the elements, said chordal portions extending to the reactance track portions of said elements and defining tangential load reactance track portions between the curved track portions of the elements when the elements are separated.

6. In a. hydraulic pump or motor of the rotary radial plunger type, including a casing, a rotatable barrel, and a plurality of plunger and cylinder assemblies carried by the barrel, valve means for the assemblies, adjustable reactance means for the assemblies providing a continuous reactance track for the assemblies in all adjusted positions of said reactance means, said means including a pair of symmetrical separable reactance elements arranged diametrically opposite to each other and movable toward and away from the axis of rotation of the barrel, said elements having symmetrical curved reactance track portions defining a continuous load reactance track coaxial with the barrel when the elements are in their innermost adjusted position, supporting means for the elements mounted in the casing, said supporting means having slide bearing surfaces in sliding engagement with the elements adjacent the ends of the elements for supporting and guiding the elements during adjustment thereof and having chordal portions bridging the space occasioned between the elements consequent upon separation of the elements from each other, said chordal portions extending to the reactance track portions of the elements, and defining tangential load reactance track portions between the track portions of the elements when the elements are separated.

'7. Inc. hydraulic pump or motor of the rotary radial plunger type including a casing, a rotatable barrel, and a plurality of plunger and cylinder assemblies carried thereby, valve means for the assemblies, adjustable reactance means for the assemblies in all adjusted positions of said reactance means, said reactance means including a pair of symmetrical separable reactance elements arranged diametrically opposite to each other, each element being movable toward and away from the axis of rotation of the barrel. said elements having reactance track portions defining a continuous track when the elements are adjusted to their innermost position, said casing having is inner cylindrical wall coaxial with the axis of rotation of the barrel, bearing blocks for the elements having cylindrical back surfaces mating with the cylindrical wall of the casing and having-chordal inner bearing surfaces respectively, said elements having outer chordal bearing surfaces adjacent their ends, the chordal sur-,

faces of each block engaging the chordal surfaces of the adjacent ends of the elements for slidably supporting the elements in the casing, means on the blocks for bridging the space occasioned between the elements consequent upon separation of the elements and defining reactance track portions between the track portions oi! the elements when the elements are separated, and

said elements having cylindrical back waves of the same radius as the cylindrical casing wall and fitting the casing wall when the elements are moved to their outermost position, whereby the entire reactance track is directly supported by the casing wall during maximum stroke.

8. In a hydraulic pump or motor of the rotary radial plunger type including a casing, a rotatable barrel, a plurality of plunger and cylinder assemblies carried thereby, valve means for the assemblies, adjustable reactance means therefor, said reactance means including a pair of diametrically separable load reactance track elements, parallel guide means carried in the casing and engaging said elements and supporting the same for radial movement toward and away from each other to change the contour oi the track, said reactance elements having outer cylindrical surface portions, and said casing having internal cylindrical surface portions coaxial with the barrel and surrounding and complementary to and fitting the cylindrical surface portions of the reactance elements respectively, and co-extensive therewith, when the elements are moved a maximum distance apart, whereby upon separation of the elements to the extreme separated position, the complementary surfaces of the elements and easing engage and each element is fully supported by the casing for resistlng hydraulic load.

9. In a pump or motor of the radial piston type, a rotatable barrel, a plurality of plunger and cylinder assemblies carried thereby, valve means for the assemblies, adjustable reactance means comprising two fixed straight load track members oppositely disposed with respect to the carrier axis, and two adjustable load track members supported on and slidable with respect to the fixed track members and disposed opposite to each other between the fixed tracks, each adjustable track member having a curved track surface, the ends of which terminate in tangential relation to the fixed track members to form therewith a complete rigid track annulus of variable dimensions symmetrical about the carrier axis, and means on the plungers in rolling engagement with said annulus to reciprocate the plungers.

10. In a pump or motor or the character described, a casing, a valve pintle rigidly secured therein, a rotor rotatably mounted in said casing and having a central bore receiving the valve pintle, a radial flange on the barrel and having radial guideways, cooperative ports between said barrel and pintle, radial pumping units carried by said rotor and guided respectively in said guideways, reactance means surrounding said rotor and supported by the casing, actuating devices i'or the said pumping units operated by said reactance means, said reactance means including pairs of curved load track elements, the elements of each pair being spaced axially of the rotor from each other and accommodating the flange therebetween, and said pairs being adjustable radially toward and away from each other, and a pair of stationary planar load track elements having track portions at each side of the flange, said track elements conjointly forming continuous parallel load tracks at opposite sides of the flange and, variable in operating eflect, by adjustment of the curved tracks.

11. In a pump or motor of the character described, a casing having a cylindrical wall, a rotor rotatably mounted in-said casing, a radial series of pumping units including pistons driven -by the rotor, valve means therefor, reactance means surrounding the rotor and supiwrted by;

the casing, said means including a pair of adjustable separable members having curved working contours, piston actuating devices for the pistons of said pumping units and operatedby said reactance means, means associated with said reactance means for moving the adjustable members toward and away from each other to change the working contour of said reactance means symmetrically on opposite sides of the rotor aids and to thereby change the stroke of the pistons, said reactance means including a pair of diametrally opposite stationary members having cylindrical back surfaces in mating relation with said cylindrical casing and supported thereby,

and track surfaces cooperating with the piston actuating devices, the track surfaces providing continuations of the working contours oi said adjustable members in all adjusted positions thereof to form therewith a continuous track for the piston actuating devices.

12. In a hydraulic pump or motor of the rotary radial plunger type, including a casing, a rotatable barrel, a plurality of plunger and cylinder assemblies carried thereby, valve means for the assemblies, adjustable reactance means therefor providing a continuous reactance path for the assembly in all adjusted including a pair of separable reactance elements having reactance track portions arranged diametrically opposlte to and symmetrically with respect to each other, said elements being adjustable toward and away'from the axis of rotation oi! the barrel to difierent adjusted positions for adjusting the strokes of the assemblies, the reactance track portions defining a continuous track surrounding the barrel when the elements are adjusted to their innermost position, means in the casing'bridging the space between the ends of the track portions of the elements when the elements are separated and forming with the said track portions of the elements a continuous closed track, substantially the entire back surfaces of the elements providing abutment surfaces of the elements, and said casing having a wall in the plane of the elements and surrounding the same and fitting the abutment surfaces of the elements when the elements are adjusted to their outermost separated position, whereby the elements are rigidly supported against hydraulic load by the casing wall.

EIEKK-BENEDEK.

positions, said means 

